A thermoplastic composition comprises a compatibilized poly(arylene ether)/polyamide resin blend and a dendritic polyester resin.

The invention relates to a method of enhancing the melt flow characteristics of compositions comprising a compatibilized poly(arylene ether)/polyamide resin blend.
Poly(arylene ether) resins are commercially attractive materials because of their unique combination of physical, chemical, and electrical properties. Furthermore, the combination of these resins with polyamide resins into compatibilized blends results in additional overall properties such as chemical resistance and high strength. Examples of such compatibilized blends can be found in U.S. Pat. No. 4,315,086 to Ueno, et al; U.S. Pat. No. 4,659,760 to van der Meer; and U.S. Pat. No. 4,732,938 to Grant, et al. The properties of these blends can be further enhanced by the addition of various additives such as impact modifiers, flame retardants, light stabilizers, processing stabilizers, heat stabilizers, antioxidants and fillers.
The physical properties of poly(arylene ether)/polyamide blends make them attractive for a variety of end-use articles in the automotive market, especially for under hood and various exterior components. Many of these components are subjected to a variety of abuses such as impacts and as such require outstanding impact resistance and ductility. Moreover, many of these same articles are preferentially produced using conversion techniques such as injection molding. Some of the desirable applications, for example connectors, have very thin wall sections and therefore require resins that have very low viscosities in order to completely fill the molding tools. Conventional poly(arylene ether)/polyamide blends have inadequate flow properties at the processing temperatures that are needed to minimize the thermal degradation of the resins. Increasing the processing temperature to higher than these temperatures in order to reduce viscosity of the blends results in brittle parts and many surface imperfections in the final part, both of which are unacceptable.
It is therefore apparent that a need continues to exist for compatibilized poly (arylene ether)/polyamide compositions that have improved melt flow yet retain the other attractive physical properties.
The needs discussed above have been generally satisfied by the discovery of a thermoplastic composition comprising a compatibilized poly(arylene ether)/polyamide resin blend and a dendritic polyester resin.
In another embodiment, a method of enhancing the melt flow of compatibilized poly(arylene ether)/polyamide resin blends comprises intimately mixing a poly(arylene ether) resin, a polyamide resin, and a compatibilizing agent with a dendritic polyester resin.
Alternatively, a method for enhancing the melt flow of a compatibilized poly (arylene ether)/polyamide resin blend comprises intimately mixing a compatibilized poly(arylene ether)/polyamide resin blend with a dendritic polyester resin.
A thermoplastic composition comprises a compatibilized poly(arylene ether)/polyamide resin blend and a dendritic polyester resin. The inclusion of as little as 0.5 weight percent of dendritic polyester resin can increase the melt flow rate of the compatibilized poly(arylene ether)/polyamide resin blend by as much as 100%. Melt flow rate is defined as the mass of plastic melt that flows through an orifice at a defined temperature and load on the plastic melt. The melt flow rate values contained herein were determined according to ASTM method D1238 (same as ISO 1130). Due to the increased melt flow, the thermoplastic composition may be formed into articles with broad ranges of thicknesses by injection molding without degradation of physical properties such as the heat distortion temperature due to thermal degradation.
Compatibilized poly(arylene ether)/polyamide resin blends are produced by combining poly(arylene ether), polyamide and a compatibilizing agent. The term poly (arylene ether) includes polyphenylene ether (PPE) and poly(arylene ether) copolymers; graft copolymers; poly(arylene ether) ether ionomers; and block copolymers of alkenyl aromatic compounds, vinyl aromatic compounds, and poly(arylene ether), and the like; and combinations comprising at least one of the foregoing; and the like. Poly(arylene ether)s per se, are known polymers comprising a plurality of structural units of the formula (I):
wherein for each structural unit, each Q1 is independently halogen, primary or secondary lower alkyl (e.g., alkyl containing up to 7 carbon atoms), phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy, halohydrocarbonoxy wherein at least two carbon atoms separate the halogen and oxygen atoms, or the like; and each Q2 is independently hydrogen, halogen, primary or secondary lower alkyl, phenyl, haloalkyl, hydrocarbonoxy, halohydrocarbonoxy wherein at least two carbon atoms separate the halogen and oxygen atoms, or the like. Preferably, each Q1 is alkyl or phenyl, especially C1-4 alkyl, and each Q2 is hydrogen.
Both homopolymer and copolymer poly(arylene ether) are included. The preferred homopolymers are those containing 2,6-dimethylphenylene ether units. Suitable copolymers include random copolymers containing, for example, such units in combination with 2,3,6-trimethyl-1,4-phenylene ether units or copolymers derived from copolymerization of 2,6-dimethylphenol with 2,3,6-trimethylphenol. Also included are poly(arylene ether) containing moieties prepared by grafting vinyl monomers or polymers such as polystyrenes, as well as coupled poly(arylene ether) in which coupling agents such as low molecular weight polycarbonates, quinones, heterocycles and formals undergo reaction in known manner with the hydroxy groups of two poly(arylene ether) chains to produce a higher molecular weight polymer. Poly (arylene ether)s further include combinations comprising at least one of the above.
The poly(arylene ether) generally has a number average molecular weight of about 3,000-40,000 atomic mass units (amu) and a weight average molecular weight of about 20,000-80,000 amu, as determined by gel permeation chromatography. The poly(arylene ether) may have an intrinsic viscosity of about 0.10 to about 0.60 deciliters per gram (dl/g), preferably about 0.29 to about 0.48 dl/g, as measured in chloroform at 25xc2x0 C. It is also possible to utilize a high intrinsic viscosity poly(arylene ether) and a low intrinsic viscosity poly(arylene ether) in combination. Determining an exact ratio, when two intrinsic viscosities are used, will depend somewhat on the exact intrinsic viscosities of the poly(arylene ether) used and the ultimate physical properties that are desired.
Poly(arylene ether) is typically prepared by the oxidative coupling of at least one monohydroxyaromatic compound such as 2,6-xylenol or 2,3,6-trimethylphenol. Catalyst systems are generally employed for such coupling; they typically contain at least one heavy metal compound such as a copper, manganese or cobalt compound, usually in combination with various other materials.
Useful poly(arylene ether) also include those which comprise molecules having at least one aminoalkyl-containing end group. The aminoalkyl radical is typically located in an ortho position to the hydroxy group. Products containing such end groups may be obtained by incorporating an appropriate primary or secondary monoamine such as di-n-butylamine or dimethylamine as one of the constituents of the oxidative coupling reaction mixture. Also frequently present are 4-hydroxybiphenyl end groups, typically obtained from reaction mixtures in which a by-product diphenoquinone is present, especially in a copper-halide-secondary or tertiary amine system. A substantial proportion of the polymer molecules, typically constituting as much as about 90% by weight of the polymer, may contain at least one of said aminoalkyl-containing and 4-hydroxybiphenyl end groups.
It will be apparent to those skilled in the art from the foregoing that the contemplated poly(arylene ether) include all those presently known, irrespective of variations in structural units or ancillary chemical features. Poly(arylene ether) is typically employed in amounts of about 30 to about 90 weight percent, preferably about 35 to about 65 weight percent and more preferably about 40 to about 60 weight percent, based on the total weight of the composition.
Polyamide resins are a generic family of resins known as nylons, characterized by the presence of an amide group (xe2x80x94C(O)NHxe2x80x94). Nylon-6 and nylon-6,6 are the generally preferred polyamides and are available from a variety of commercial sources. Other polyamides, however, such as nylon-4,6, nylon-12, nylon-6,10, nylon 6,9, nylon 6/6T and nylon 6,6/6T with triamine contents below about 0.5 weight percent, as well as others, such as the amorphous nylons may be useful for particular PPE-polyamide applications. Mixtures of various polyamides. as well as various polyamide copolymers, are also useful. The most preferred polyamide is polyamide-6.
Polyamides can be obtained by a number of well known processes such as those described in U.S. Pat. Nos. 2,071,250; 2,071,251; 2,130,523; 2,130,948; 2,241,322; 2,312,966; and 2,512,606. Nylon-6, for example, is a polymerization product of caprolactam. Nylon-6,6 is a condensation product of adipic acid and 1,6-diaminohexane. Likewise, nylon 4,6 is a condensation product between adipic acid and 1,4-diaminobutane. Besides adipic acid, other useful diacids for the preparation of nylons include azelaic acid, sebacic acid, dodecane diacid, as well as terephthalic and isophthalic acids, and the like. Other useful diamines include m-xylene diamine, di-(4-aminophenyl)methane, di-(4-aminocyclohexyl)methane; 2,2-di-(4-aminophenyl)propane, 2,2-di-(4-aminocyclohexyl)propane, among others. Copolymers of caprolactam with diacids and diamines are also useful.
Polyamides having viscosity of up to about 400 ml/g can be used, with a viscosity of about 90 to about 350 ml/g preferred, and about 110 to about 240 ml/g especially preferred, as measured in a 0.5 wt % solution in 96 wt % sulfuric acid in accordance with ISO 307. Polyamide is typically employed in amounts of about 10 to about 70 weight percent, preferably about 20 to about 65 weight percent and more preferably about 25 to about 60 weight percent, based on the total weight of the composition.
Compatibilizing agents improve the physical properties of the poly(arylene ether)/polyamide resin blend and enable the use of a greater proportion of the polyamide component. When used herein, the expression xe2x80x9ccompatibilizing agentxe2x80x9d refers to those polyfunctional compounds which interact with the poly(arylene ether), the polyamide, or, preferably, both. This interaction may be chemical (e.g. grafting) or physical (e.g. affecting the surface characteristics of the dispersed phases). In either case the resulting poly(arylene ether)/polyamide composition appears to exhibit improved compatibility, particularly as evidenced by enhanced impact strength, mold knit line strength and/or elongation. As used herein, the expression xe2x80x9ccompatibilized poly(arylene ether)/polyamide resin blendxe2x80x9d refers to those compositions which have been physically or chemically compatibilized with an agent as discussed above, as well as those compositions which are physically compatible without such agents, as taught, for example, in U.S. Pat. No. 3,379,792.
Suitable compatibilizing agents include, for example, liquid diene polymers, epoxy compounds, oxidized polyolefin wax, quinones, organosilane compounds, polyfunctional compounds, and functionalized poly(arylene ether)s obtained by reacting one or more of the previously mentioned compatibilizing agents with poly (arylene ether).
Liquid diene polymers suitable for use as compatibilizing agents include homopolymers of a conjugated diene and copolymers of a conjugated diene with at least one monomer selected from other conjugated dienes; vinyl monomers, such as styrene and alpha-methyl styrene; olefins, such as ethylene, propylene, butene-1, isobutylene, hexene-1, octene-1, and dodecene-1, and mixtures thereof. The liquid diene polymers may have a number average molecular weight of about 150 atomic mass units (AMU) to about 10,000 AMU, preferably about 150 AMU to about 5,000 AMU. These homopolymers and copolymers can be produced by the methods described in, for example, U.S. Pat. Nos. 3,428,699, 3,876,721, and 4,054,612. Specific examples of liquid diene polymers include polybutadiene, polyisoprene, poly (1,3-pentadiene), poly(butadiene-isoprene), poly(styrene-butadiene), polychloroprene, poly(butadiene-alpha methylstyrene), poly(butadiene-styrene-isoprene), poly(butylene-butadiene), and the like, and combinations comprising at least one of the foregoing liquid diene polymers.
Epoxy compounds suitable for use as compatibilizing agents include epoxy resins produced by condensing polyhydric phenols (e.g., bisphenol-A, tetrabromobisphenol-A, resorcinol and hydroquinone) and epichlorohydrin; epoxy resins produced by condensing polyhydric alcohols (e.g., ethylene glycol, propylene glycol, butylene glycol, polyethylene glycol, polypropylene glycol, pentaerythritol and trimethylolethane and the like) and epichlorohydrin, glycidyl etherified products of monohydric alcohols and monohydric phenols, such as phenyl glycidyl ether, butyl glycidyl ether and cresyl glycidyl ether; glycidyl derivates of amino compounds, such as the diglycidyl derivate of aniline; epoxidized products of higher olefinic or cycloalkene, or natural unsaturated oils (e.g., soybean oil) as well as of the foregoing liquid diene polymers; combinations comprising at least one of the foregoing epoxy compounds; and the like.
Oxidized polyolefin waxes suitable for use as compatibilizing agents are well known and described, for example, in U.S. Pat. Nos. 3,756,999 and 3,822,227. Generally, these are prepared by an oxidation or suspension oxidation of polyolefin. An especially preferred oxidized polyolefin wax is xe2x80x9cHoechst Wachsxe2x80x9d.
Quinone compounds suitable for use as compatibilizing agents are characterized as having at least one six-member carbon ring; at least two carbonyl groups, which may be in the same or different six-member carbon rings, provided that they occupy positions corresponding to the 1,2- or 1,4-orientation of the monocyclic quinone; and at least two carbon-carbon double bonds in the ring structure, the carbon-carbon double bounds and carbonyl carbon-oxygen double bonds being conjugated with respect to each other. Where more than one ring is present in the unsubstituted quinone, the rings may be fused, non-fused, or both: Non-fused rings may be bound by a direct carbon-carbon double bond or by a hydrocarbon radical having conjugated unsaturation such as xe2x80x94Cxe2x95x90Cxe2x80x94Cxe2x95x90Cxe2x80x94.
The quinones may be substituted or unsubstituted. In substituted quinones, the degree of substitution may be from one to the maximum number of replaceable hydrogen atoms. Exemplary substituents include halogen (e.g. chlorine, bromine, fluorine, etc.), hydrocarbon radicals including branched and unbranched alkyl, cycloalkyl, olefinically unsaturated hydrocarbon radicals, aryl, alkylaryl, and halogenated derivatives thereof; and similar hydrocarbons having heteroatoms therein, particularly oxygen, sulfur, or phosphorous, and wherein the heteroatom connects the radical to the quinone ring (e.g., alkoxyl). Examples of specific quinones include 1,2-benzoquinone, 1,4-benzoquinone, 2,2xe2x80x2-diphenoquinone, 4,4xe2x80x2-diphenoquinone, 2,2xe2x80x2,6,6xe2x80x2-tetramethyl-4,4xe2x80x2-diphenoquinone, 1,2-naphthoquinone, 1,4-naphthoquinone, 2,6-naphthoquinone, chloranils, 2-chloro-1,4-benzoquinone, 2,6-dimethyl-1,4-benzoquinone, combinations comprising at least one of the foregoing quinones, and the like.
Organosilane compounds suitable as compatibilizing agents are characterized as having at least one silicon atom bonded to a carbon through an oxygen link and at least one carbon-carbon double bond or carbon-carbon triple bond and/or a functional group selected from an amine group or a mercapto group, provided that the functional group is not directly bonded to the silicon atom. In such compounds, the Cxe2x80x94Oxe2x80x94Si component is generally present as an alkoxy or acetoxy group bonded directly to the silicon atom, wherein the alkoxy or acetoxy group generally has less than 15 carbon atoms and may also contain hetero atoms (e.g., oxygen). Additionally, there may also be more than one silicon atom in the compound, such multiple silicon atoms, if present, being linked through an oxygen link (e.g., siloxanes); a silicon-silicon bond; or a divalent hydrocarbon radical (e.g., methylene or phenylene groups); or the like. Examples of suitable organosilane compounds include gamma-aminopropyltriethoxysilane, 2-(3-cyclohexanyl)ethyltrimethoxysilane, 1,3-divinyltetraethoxysilane, vinyl-tris-(2-methoxyethoxy)silane, 5-bicycloheptenyltriethoxysilane, and gamma-mercaptopropyltrimethoxysilane.
Polyfunctional compounds suitable as compatibilizing agents include three types. The first type of polyfunctional compounds are those having in the molecule both a carbon-carbon double bond or a carbon-carbon triple bond and at least one carboxylic acid, anhydride, amide, ester, imide, amino, epoxy, orthoester, or hydroxy group. Examples of such polyfunctional compounds include maleic acid, maleic anhydride, fumaric acid, glycidyl acrylate, itaconic acid, aconitic acid, maleimide, maleic hydrazide, reaction products resulting from a diamine and maleic anhydride, dichloro maleic anhydride, maleic acid amide, unsaturated dicarboxylic acids (e.g. acrylic acid, butenoic acid, methacrylic acid, ethylacrylic acid, pentenoic acid), decenoic acids, undecenoic acids, dodecenoic acids, linoleic acid, esters of the foregoing unsaturated carboxylic acids, acid amides of the foregoing unsaturated carboxylic acids, anhydrides of the foregoing unsaturated carboxylic acids, unsaturated alcohols (e.g. alkyl alcohol, crotyl alcohol, methyl vinyl carbinol, 4-pentene-1-ol, 1,4-hexadiene-3-ol, 3-butene-1,4-diol, 2,5-dimethyl-3-hexene-2,5-diol and alcohols of the formula CnH2n-5OH, CnH2n-7OH and CnH2n-9 OH, wherein n is a positive integer up to 30), unsaturated amines resulting from replacing from replacing the xe2x80x94OH group(s) of the above unsaturated alcohols with NH 2 groups, functionalized diene polymers and copolymers, and the like. Of these, two of the preferred compatibilizing agents for compositions of the present invention are maleic anhydride and fumaric acid.
The second group of polyfunctional compounds have both (a) a group represented by the formula (OR) wherein R is hydrogen or an alkyl, aryl, acyl, or carbonyl dioxy group, and (b) at least two groups each of which may be the same or different selected from carboxylic acid, acid halide, anhydride, acid halide anhydride, ester, orthoester, amide, imido, amino, and various salts thereof. Typical of this group of compatibilizers are the aliphatic polycarboxylic acids, acid esters and acid amides represented by the formula:
(RIO)mR(COORII)n(CONRIIIRIV)s
wherein R is a linear or branched chain, saturated aliphatic hydrocarbon of from 2 to 20, preferably 2 to 10, carbon atoms; RI is hydrogen or an alkyl, aryl, acyl or carbonyl dioxy group of 1 to 10, preferably 1 to 6, more preferably 1 to 4, carbon atoms, especially preferred is hydrogen; each RII is independently hydrogen or an alkyl or aryl group from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms; each R III an R IV are independently hydrogen or an alkyl or aryl group of from 1 to 10, preferably from 1 to 6, most preferably 1 to 4, carbon atoms; m is equal to 1 and (n+s) is greater than or equal to 2, preferably equal to 2 or 3, and n and s are each greater than or equal to zero and wherein (ORI) is alpha or beta to a carbonyl group and at least two carbonyl groups are seperated by 2 to 6 carbon atoms. Obviously, R I, RII, RIII and RIV cannot be aryl when the respective substituent has less than 6 carbon atoms.
Suitable polycarboxylic acids include, for example, citric acid, malic acid, agaricic acid, and the like; including the various commercial forms thereof, such as for example, the anhydrous and hydrated acids. Of these, citric acid is another of the preferred compatibilizing agents. Illustrative of esters useful herein include, for example, acetyl citrate and mono- and/or distearyl citrates and the like. Suitable amides useful herein include, for example, N,Nxe2x80x2-diethyl citric acid amide, N-phenyl citric acid amide, N-dodecyl citric acid amide, N,Nxe2x80x2-didodecyl citric acid amide, and N-dodecyl malic acid. Especially preferred derivates are the salts thereof, including the salts with amines and/preferably, the alkali and alkaline earth metal salts. Exemplary of suitable salts include calcium maleate, calcium citrate, potassium maleate, and potassium citrate.
The third group of polyfunctional compounds have both (a) an acid halide group, most preferably an acid chloride group and (b) at least one carboxylic acid, anhydride, ester, epoxy, orthoester, or amide group, preferably a carboxylic acid or anhydride group. Examples of compatibilizers within this group include trimellitic anhydride acid chloride, chloroformyl succinic anhydride, chloro formyl succinic acid, chloroformyl glutaric anhydride, chloroformyl glutaric acid, chloroacetyl succinic anhydride, chloroacetylsuccinic acid, trimellitic acid chloride, and chloroacetyl glutaric acid. Among these, trimellitic anhydride acid chloride is preferred. Furthermore, it is especially preferred that compatibilizers of this group be prereacted with at least a portion of the poly(arylene ether) whereby the compatibilizing agent is a poly(arylene ether)-functionalized compound.
Preferred compatibilizing agents include citric acid, maleic acid, maleic anhydride, malic acid, fumaric acid, and the like, and combinations comprising at least one of the foregoing compatibilizing agents.
The above and other compatibilizing agents are more fully described in U.S. Pat. Nos. 4,315,086; 4,600,741; 4,642,358; 4,826,933; 4,866,114, 4,927,894; 4,980,424; 5,041,504; and 5,115,042.
The foregoing compatibilizing agents may be used alone or in various combinations of one another with another. Furthermore, they may be added directly to the melt blend or pre-reacted with either or both the poly(arylene ether) and polyamide, as well as with other resinous materials employed in the preparation of the compositions of the present invention. With many of the foregoing compatibilizing agents, particularly the polyfunctional compounds, even greater improvement in compatibility is found where at least a portion of the compatibilizing agent is pre-reacted, either in the melt or in a solution of a suitable solvent, with all or a part of the poly(arylene ether). It is believed that such pre-reacting may cause the compatibilizing agent to react with the polymer and, consequently, functionalize the poly(arylene ether) as noted above. For example, the poly(arylene ether) may be pre-reacted with maleic anhydride to form an anhydride functionalized poly(arylene ether) that has improved compatibility with the polyamide compared to a non-functionalized poly (arylene ether).
Where the compatibilizing agent is employed in the preparation of the compatibilized poly(arylene ether)/polyamide resin blend, the initial amount used will be dependent upon the specific compatibilizing agent chosen and the specific polymeric system to which it is added. Typically, the compatibilizing agent may be present in an amount of about 0.05 weight percent to about 5 weight percent. Within this range, the compatibilizing agent amount may preferably be at least about 0.1 weight percent, more preferably at least about 0.3 weight percent, yet more preferably at least about 0.5 weight percent. Also within this range, it may be preferred to use a compatibilizing agent amounts up to about 2 weight percent, more preferably up to about 1 weight percent, based on the total weight of the composition.
The dendritic polyester resin comprises a starburst configuration with polyester branching units bound to a core. Optionally the polyester branching units have hydroxy functional groups at the terminal end that provide hydroxy groups at the periphery of the dendritic polymer. A portion of the terminal hydroxyl groups on the dendritic resin may be reacted to provide chain termination or functional groups. The dendritic polyester resin preferably has a weight average molecular weight, as determined by gel permeation chromatography, within the range of 1,000 to 5,000. The composition preferably comprises less than about 15 weight percent (wt %), preferably less than about 10 wt %, and more preferably less than about 6 wt % of the dendritic polyester resin based on the total weight of the composition.
The term dendritic polyester resin as used herein refers to both dendrimers and hyperbranched polymers known in the art comprising polyester branching units. Dendrimers and hyperbranched polymers suitable for use in this invention are well defined, highly branched macromolecules that radiate from a central core and are synthesized through a stepwise repetitive branching reaction sequence. Those preferred herein are the star or starburst dendritic polymers having a multifunctional core with radial branching units which extend from the core. The repetitive branching sequence typically guarantees complete shells for each generation, lending to polymers that are typically monodisperse. The synthetic procedures for dendritic polymer preparation often provide nearly complete control over the size, shape, surface/interior chemistry, flexibility and topology. This invention includes the use of dendritic polymers with complete and symmetrical branches as well as incomplete and asymmetric branches. An example of a suitable synthesis method is to employ a multifunctional compound, such as ethylene diamine, as a core building block. This multifunctional core is first reacted with acrylonitrile to provide a structure with four nitrile groups. These nitrile groups are reduced to amine units to complete the first cycle. Further reaction cycles prepare dendritic polymers with 8, 16, 32, 64, 128, etc. primary amino groups. The terminal ends of these branching units can be functionalized, if desired, with conventional functional units for dendritic polymers such as hydroxy groups, epoxy groups and ether groups.
The weight average molecular weight of preferred dendritic polyester resins can be about 1,000 to about 21,000 and is preferably about 1,500 to about 12,000, as determined by gel permeation chromatography. When attempting to increase melt flow, the most preferred values are at the low end of the molecular weight range of about 1,500 to about 5,000. Preferably the dendritic polyester resins have a narrow polydispersity of about 1.3 to about 1.5 and a melt viscosity of 1 to 250 Pa at a temperature of 110xc2x0 C. and shear rate of 30 secxe2x88x921. The dendritic polyester resins can optionally be functionalized either in the core or at the periphery of the branching units. Polar groups and non-polar groups may be bonded to the periphery of the dendritic polyester resin as desired, depending on the nature of the thermoplastic composition formulation. Preferably, hydroxy and/or epoxy groups are bound at the terminal ends of the dendritic polyester resins.
The molecules that can be used as a core contain at least one functional group and preferably contain multiple functional groups. These include ammonia, methanol, polymethylene diamines, diethylene triamine, triethylene tetramine, tetraethylene pentamine, linear and branched polyethylene imine, methylamine, hydroxyethylamine, octadecylamine, polyaminoalkylarenes, heterocyclic amines such as imidazolines and piperidines, morpholine, piperazine, pentaerythritol, sorbitol, mannitol, polyalkylenepolyols such as polyethylene glycol and polypropylene glycol, glycols such as ethylene glycol, polyalkylene polymercaptans, phosphine, glycine, thiophenols, phenols, melamine and derivatives thereof such as melamine tris (hexamethylenediamine).
Preferred dendritic polymers are sold under the trademark BOLTORN(copyright) available from Perstorp Specialty Chemicals, Perstorp, Sweden. Of this series, BOLTORN H20 and BOLTORN H30 dendritic polymers, which are functionalized with hydroxy groups at the periphery, are preferred and have a weight average molecular weight in the range of about 1,000 to about 4,000.
Suitable central initiator molecules for the polyester type dendritic polymers include cycloaliphatic or aromatic diols, triols, tetraols, sorbitol, manitol, dipentaerythritol, a monofunctional alcohol and an alkoxylate polymer having a molecular weight less than 2000. Examples of suitable diols include 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 1,2-ethanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and polytetrahydrofuran.
Suitable polyester chain extenders are monofunctional carboxylic acids having at least two hydroxyl groups such as xcex1, xcex1-bis(hydroxymethyl)-propionic acid, xcex1, xcex1-bis(hydroxymethyl)-butyric acid, xcex1, xcex1, xcex1-tris(hydroxymethyl)-acetic acid, xcex1, xcex1-bis(hydroxymethyl)-butyric acid, xcex1, xcex1-bis(hydroxymethyl)-propionic acid, xcex1, xcex2-dihydroxypropionic acid, heptonic acid, citric acid, d- or l- tartaric acid or xcex1-phenylcarboxylic acids such as 3,5-dihydroxybenzoic acid.
The optional chain terminating agents which can be used include saturated monofunctional carboxylic acids, saturated fatty acids, unsaturated monofunctional carboxylic acids, aromatic monofunctional carboxylic acids such as benzoic acid and difunctional or polyfunctional carboxylic acids or anhydrides thereof. An example is behenic acid. Terminal hydroxyl groups in the polyester chain extender can be reacted with chain stoppers with or without functional groups. Suitable polyester-based dendritic polymers are described in U.S. Pat. Nos. 5,418,301 and 5,663,247.
Other suitable chain extenders include aliphatic di, tri or polyhydroxyfunctional saturated or unsaturated monocarboxylic acids, cycloaliphatic di, tri or polyhydroxyfunctional saturated or unsaturated monocarboxylic acids, aromatic di, tri or polyhydroxyfunctional monocarboxylic acids, aliphatic monohydroxyfunctional saturated or unsaturated di, tri or polycarboxylic acids, cycloaliphatic monohydroxy functional saturated or unsaturated di, tri or polyhydroxycarboxylic acids and aromatic monohydroxy functional di, tri or polycarboxylic acids. The esters of the above acids are also suitable.
The dendritic polyester resin is preferably used in the compositions of this invention in an amount of about 0.01 to about 15 wt % of the total composition to provide a useful balance of properties. More preferably, an amount of dendritic polyester resin of about 0.1 to about 10 wt % of the total composition is used to improve flow and even more preferably, about 0.1 to about 6 wt % of the total composition and most preferably about 0.1 to about 4 wt % of the total composition is used to improve flow while minimizing the loss of heat distortion temperature (HDT) values. Although not preferred, the dendritic polyester resin can be used in amounts up to 30 wt %.
The thermoplastic composition may further comprise an optional impact modifier. Particularly suitable thermoplastic impact modifiers are block copolymers, for example, A-B diblock copolymers and A-B-A triblock copolymers having of one or two alkenyl aromatic blocks A, which are typically styrene blocks, and a rubber block, B, which is typically an isoprene or butadiene block. The butadiene block may be partially hydrogenated. Mixtures of these diblock and triblock copolymers are especially useful.
Suitable A-B and A-B-A copolymers include but are not limited to polystyrene-polybutadiene, polystyrene-poly(ethylene-propylene), polystyrene-polybutadiene, poly (xcex1-methylstyrene)-polybutadiene, polystyrene-polybutadiene-polystyrene (SBS), polystyrene-poly(ethylene-propylene)-polystyrene, polystyrene-polyisoprene-polystyrene and poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene), as well as the selectively hydrogenated versions thereof, and the like. Mixtures of the aforementioned block copolymers are also useful. Such A-B and A-B-A block copolymers are available commercially from a number of sources, including Phillips Petroleum under the trademark SOLPRENE, Shell Chemical Co., under the trademark KRATON, Dexco under the trademark VECTOR, and Kuraray under the trademark SEPTON.
A useful amount of impact modifier is up to about 20 weight percent (wt %), with about 1 wt % to about 15 wt % preferred, and about 2 wt % to about 12 wt % especially preferred, wherein the weight percentages are based on the entire weight of the composition. In an especially preferred embodiment, the impact modifier comprises a polystyrene-polybutadiene-polystyrene block copolymer.
Additionally, the thermoplastic resin composition may optionally also contain various additives, such as antioxidants, fillers and reinforcing agents, mold release agents, UV absorbers, stabilizers such as light stabilizers and others, lubricants, plasticizers, pigments, dyes, colorants, anti-static agents, and flame retardants.
The compositions may be prepared by well-known procedures. One method of preparation is to blend the dendritic polyester resin with the poly(arylene ether), polyamide, and compatibilizing agent and compound the mixture by known techniques such as within an extruder to form a blend. Alternatively, the dendritic polyester resin can be blended and compounded with a compatibilized poly(arylene ether)/polyamide blend. Regardless of the method of preparation, the composition has a reduced viscosity and increased flow as compared to the compatibilized poly (arylene ether)-polyamide composition alone without a significant reduction in HDT values. This composition can be blended with other components or extruded, quenched and chopped into pellets. These pellets can then be melted and molded into articles of a desired shape and size or compounded again to blend with other components before additional processing in preparing finished articles.
The invention is further illustrated by the following non-limiting examples. All cited patents are herein incorporated by reference.

High flow compositions of compatibilized poly(arylene ether) polyamide blends


First, an authentication module may receive an identification (ID) linking request, create a secured ID linking request from the ID linking request, and send the secured ID linking request to a packet gateway module located in a packet core of a mobile network. Next, the packet gateway module may insert into the secured ID linking request, an encrypted version of a mobile identifier corresponding to a client device from which the secured ID linking request was received. Next, a mobile video session manager module may receive from the packet gateway module, the secured ID linking request and link a subscriber of a managed video service corresponding to a video identifier to the client device corresponding to the mobile identifier. A policy corresponding to the subscriber of the managed video service may then be applied to flows over the packet core to and from the client device.

In telecommunication, Long-Term Evolution (LTE) is a standard for high-speed wireless communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA technologies. It increases the capacity and speed using a different radio interface together with core network improvements. The standard is developed by the 3GPP (3rd Generation Partnership Project). LTE is the upgrade path for carriers with both GSM/UMTS networks and CDMA2000 networks. The different LTE frequencies and bands used in different countries mean that only multi-band phones are able to use LTE in all countries where it is supported.

Updating policy for a video flow during transitions


A method of making antacid coated chewing gum products comprises the steps of providing chewing gum cores; providing a coating syrup comprising a bulk sweetener and calcium carbonate having a median particle size of greater than about 3 microns and being suspended in the coating syrup; and applying the coating syrup to the cores and drying the syrup to produce a coating on the cores, the coating containing from about 25% to about 60% calcium carbonate.

The present invention relates to methods for producing coated chewing gum products. More particularly, the invention relates to producing coated chewing gum products containing an antacid which is added to the chewing gum coating such that it will have a controlled fast release from chewing gum for maximum effectiveness.
Coated chewing gum products are well known. Many prior art patents disclose chewing gum products coated with sugar sweeteners or polyol sweeteners. U.S. Pat. No. 4,317,838, for example, discloses a method of applying a sugarless coating to chewing gum. The coating may include calcium carbonate as an anti-sticking agent. Synthetic sweeteners, including many different high-intensity sweeteners, are also suggested for use in the coating.
Another area of interest is the use of medicaments in chewing gum. In some instances, it is contemplated that an active medicament that is added to the chewing gum may be released readily. An active medicament may be added to the gum coating, which is a water soluble matrix, such that during the chewing period, the medicament may be released quickly, resulting in a fast release. This would allow a chewing gum coating to be a carrier for an active medicament, specifically an antacid with these fast release characteristics. For example, U.S. Pat. No. 4,867,989 discloses a chewing gum composition coated with an outer shell containing layers of a mineral compound and a coating syrup, but this patent states that the mineral compound must be added separately and not dispersed in the syrup used to make the coating.
Antacids are usually taken on an xe2x80x9cas neededxe2x80x9d basis to relieve gastrointestinal disturbances mostly due to dietary indiscretions. These antacids are generally insoluble inorganic salts such as calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, or aluminum hydroxide. Antacids readily neutralize acids in the gastrointestinal (GI) tract and are commonly available in or as antacid tablets.
Previously, antacids have been added to chewing gum and in a chewing gum coating, but some products have not been totally consumer acceptable. The large amount of active antacid needed for effectiveness does not lend itself to giving a good tasting product. Also, the presence of sugar in the antacid chewing gum or coated on the chewing gum of some products is not consumer acceptable because sugar causes dental caries.
A sugarless coated chewing gum produced having an antacid in a sorbitol base coating is currently being sold under the trademark CHOOZ(copyright) . It has been found that by adding the antacid to a gum coating, the antacid is quickly released from the chewing gum into saliva and into the gastrointestinal (GI) tract. Relief from GI disturbances is quickly obtained, but does not last long. It would be desirable to have not only fast relief, but relief of longer duration. Thus, there is a need for a way to make coated chewing gum products that have a prolonged effectiveness of the antacid, as well as being acceptable to the consumer from taste and other standpoints.
It has been found that an antacid having a median particle size of at least about 3 microns can be used to make a coating with a high level of antacid, and that this antacid gives a prolonged effectiveness. Also, it has surprisingly been found that the antacid, like calcium carbonate, can be added as a suspension to the coating syrup to thus be included in the gum coating.
In a first aspect, the invention is a method of making antacid coated chewing gum products comprising the steps of providing chewing gum cores; providing a coating syrup comprising a bulk sweetener and calcium carbonate having a median particle size of greater than about 3 microns and being suspended in the coating syrup; and applying the coating syrup to the cores and drying the syrup to produce a coating on the cores, the coating containing from about 25% to about 60% calcium carbonate.
In a second aspect, the invention is a method of delivering an antacid to an individual that provides relief in the gastrointestinal tract comprising the steps of providing chewing gum cores; providing a coating syrup comprising a bulk sweetener and calcium carbonate having a median particle size of greater than about 3 microns and being suspended in the coating syrup; applying the coating syrup to the cores and drying the syrup to produce a coating on the cores, the coating containing from about 25% to about 60% calcium carbonate; and chewing the antacid coated chewing gum product in the mouth and swallowing the coating, the coating dispersing and dissolving to provide calcium carbonate as an antacid in the gastrointestinal tract.
Preferred embodiments of the invention include the addition of histamine H2-receptor antagonists. These agents inhibit or block the secretion of gastric acid by binding to a specific histamine receptor on the parietal (acid secreting) cell membranes located in the stomach. These agents, which may be added to the chewing gum center or to the antacid coating containing calcium carbonate, are used for extended relief of gastrointestinal disturbances and extended relief from stomach acidity. Examples of histamine H2-receptor antagonists are cimetidine, ranitidine, nizatidine and famotidine, with famotidine being preferred.
It is believed that providing a larger particle size antacid in a chewing gum coating makes it more effective and longer lasting. Thus, an advantage of an embodiment of the present invention is administering an antacid to an individual that has a larger particle size than is typically administered orally, giving extended relief while still achieving the effect of fast relief.
As used herein, the term xe2x80x9cchewing gumxe2x80x9d includes bubble gum and all other types of chewing gum. Unless specified otherwise, all percentages are weight percentages.
As mentioned above, products made by the present invention will include an antacid, such as calcium carbonate. The antacid will preferably be included as part of the coating syrup used to prepare a coated chewing gum product. A typical syrup may contain a polyol, suspended calcium carbonate, a binding agent, a high intensity sweetener and a whitener.
In a preferred embodiment of the present invention, the antacid is contained in the coating of chewing gum products, which allows a chewing gum coating to be a carrier for the antacid. Accordingly, as the chewing gum is chewed, the active antacid in the gum coating is released into the saliva and ingested to give relief from gastrointestinal disturbances in the GI tract.
The preferred antacids are generally carbonate or hydroxide salts of calcium, magnesium, aluminum, or bismuth, and are generally very water insoluble. Other antacids such as sodium bicarbonate, calcium bicarbonate, and other carbonates, silicates, and phosphates are included in this invention. When these materials are mixed with acids in the GI tract, the acids are readily neutralized to give relief from GI disturbances. Some typical consumer antacid products are: TUMS, which contains calcium carbonate; MILK of MAGNESIA, which contains magnesium hydroxide, and MAALOX PLUS, which contains a combination of aluminum hydroxide and magnesium hydroxide.
For antacid chewing gum products, calcium carbonate is the most preferred antacid material. This is mostly due to the fact that the most common inert filler in chewing gum base is calcium carbonate. Calcium carbonate, along with talc, which is commonly used in bases for gum products that contain food acids to give tartness to flavors, have been used as fillers in gum base and gum products for many years.
Chewing gum bases that contain calcium carbonate do not readily release their calcium carbonate during chewing. Since calcium carbonate (or in other cases talc) is very water insoluble, it releases from gum either very slowly or over very long extended chewing. As a result, this calcium carbonate is not effective as an antacid. Generally, when calcium carbonate is added to a gum formulation separate from the gum base, calcium carbonate becomes intimately mixed with the base during chewing and also releases slowly. However, when calcium carbonate is used in the coating of the chewing gum, it does become quickly available in the oral cavity and is ingested to be an effective antacid.
Generally, suspension coatings with calcium carbonate for an antacid gum may be made with sugar. Sugar with its naturally sweet taste masks some of the off-taste due to the use of high levels of calcium carbonate. With the advent of new coating technologies using less sweet sugarless polyols instead of sugar, the sweet taste of the coating is significantly reduced. In some coatings where xylitol is used, it is sufficiently sweet as a coating, but other polyols such as maltitol, hydrogenated isomaltulose, sorbitol, or erythritol, are not. When the coating contains high levels of calcium carbonate, the polyols generally lack sufficient sweetness to give a good tasting product. As a result, high-intensity sweeteners are preferably added to the coating containing calcium carbonate to give a high-quality, consumer-acceptable product.
For coated antacid chewing gum type products, the high level of calcium carbonate or other antacid in the coating modifies the taste quality and gum texture. The addition of high-intensity sweeteners to the gum coating improves the taste of the finished product. This also occurs in sugar coated gums as well as polyol coated gums, so aspartame or other high-intensity sweeteners may also be added to sugar coated gums with calcium carbonate or other antacids. If the high-intensity sweeter is subject to degradation, it may preferably be added as part of a different coating syrup from the coating syrup containing the calcium carbonate, as disclosed in U.S. patent application Ser. No. 09/591,256 filled Jun. 9, 2000, hereby incorporated by reference.
Since calcium carbonate is very water insoluble, as are many of the other neutralizing antacids, the reaction rate of the salts with aqueous acids is dependant on the surface area of the neutralizing agent. Neutralizing agents with a large surface area will react faster with acids than those with a small surface area. Many smaller size particles with a combined large surface area neutralize acids faster than fewer large particles with a combined small surface area. However, larger particle sizes of calcium carbonate give longer lasting relief from stomach acidity. When the calcium carbonate particles are suspended in a coating syrup and applied as a gum coating, the particle sizes of calcium carbonate remains essentially the same throughout the process.
Analysis of a precipitated calcium carbonate having a median particle size of about 5 microns was done before and after being applied as a coating. Before coating, the sample was analyzed and found to have a median particle size of 5.1 microns. After preparing the sample of calcium carbonate in a suspension and applying it to a gum pellet for an antacid gum product, the particle size of the calcium carbonate was 4.9 microns.
It has been determined in the tests shown below that a calcium carbonate having a median particle size of about 3 microns or greater is sufficient to give longer lasting relief of excess stomach activity.
In terms of water solubility, larger particles have a tendency to dissolve more slowly in water, and as calcium carbonate dissolves, it neutralizes stomach acidity. Smaller particles of calcium carbonate could react faster, and larger particles would react slower.
In addition to the particle size of calcium carbonate, different crystal structures have an effect on the rate of dissolution and the rate of neutralization. Natural forms of calcium carbonate such as Calcite, Aragonite, and Vaterite are highly crystalline forms of calcium carbonate and could dissolve more slowly to give longer lasting neutralizing effect. Marble, Dolomite, and even Mollusk shells are made of amorphous forms of calcium carbonate, and could dissolve faster and neutralize acidity faster than crystalline forms. Precipitated calcium carbonate, which is purified from natural sources, is a xe2x80x9cmicroxe2x80x9d crystalline form and would dissolve quickly and neutralizes acidity quickly.
Preferred precipitated calcium carbonate materials may be purchased from Specialty Minerals Inc., 260 Columbia Street, Adams, Mass., 01220. Presently preferred are the CalEssence(trademark) 300 PCC, CalEssence(trademark) 450 PCC and MD-1503 (to be CalEssence(trademark) 1500 PCC) grades of precipitated calcium carbonate. These three grades have a median particle size of 3.0, 4.5 and 15.0 microns, respectively; a surface area of 3.0, 2.2 and 2.0 meters2/gram respectively; and a tapped density of 0.85, 1.10 and 1.45 grams/cc respectively. CalEssence(trademark) 300 PCC and CalEssence(trademark) 450 PCC have a cubic shape, whereas MD-1503 has a semi-regular prismatic shape. CalEssence(trademark) 300 has a particle size distribution from essential 1 to 10 microns, with roughly 50% by weight of the particles between 3 and 10 microns. CalEssence(trademark) 450 has a particle size distribution from essentially 1 to 20 microns, with roughly 50% by weight of the particles between 4.5 and 20 microns. Preferred precipitated calcium carbonate materials will have a surface area of less than 3 meter2/gram, and a tapped density of greater than 0.7, and preferably greater than 0.8 grams/cc.
In general, a chewing gum composition typically comprises a water-soluble bulk portion, a water-insoluble chewable gum base portion and typically water-insoluble flavoring agents. The water-soluble portion dissipates with a portion of the flavoring agent over a period of time during chewing. The gum base portion is retained in the mouth throughout the chew.
The insoluble gum base generally comprises elastomers, resins, fats and oils, softeners and inorganic fillers. The gum base may or may not include wax. The insoluble gum base can constitute approximately 5% to about 95% by weight of the chewing gum, more commonly the gum base comprises 10% to about 50% of the gum, and in some preferred embodiments approximately 25% to about 35% by weight, of the chewing gum. In pellet gum center formulations, the level of insoluble gum base may be much higher.
In a preferred embodiment, the chewing gum base of the present invention contains about 20% to about 60% by weight synthetic elastomer, about 0% to about 30% by weight natural elastomer, about 5% to about 55% by weight elastomer plasticizer, about 4% to about 35% by weight filler, about 5% to about 35% by weight softener, and optional minor amounts (about 1% or less by weight) of miscellaneous ingredients such as colorants, antioxidants, etc.
Synthetic elastomers may include, but are not limited to, polyisobutylene with GPC weight average molecular weights of about 10,000 to about 95,000, isobutylene-isoprene copolymer (butyl elastomer), styrene-butadiene, copolymers having styrene-butadiene ratios of about 1:3 to about 3:1, polyvinyl acetate having GPC weight average molecular weights of about 2,000 to about 90,000, polyisoprene, polyethylene, vinyl acetate - vinyl laurate copolymers having vinyl laurate contents of about 5% to about 50% by weight of the copolymer, and combinations thereof.
Preferred ranges are: 50,000 to 80,000 GPC weight average molecular weight for polyisobutylene; 1:1 to 1:3 bound styrene-butadiene for styrene-budadiene; 10,000 to 65,000 GPC weight average molecular weight for polyvinyl acetate, with the higher molecular weight polyvinyl acetates typically used in bubble gum base; and a vinyl laurate content of 10-45% for vinyl acetate-vinyl laurate.
Natural elastomers may include natural rubber such as smoked or liquid latex and guayule, as well as natural gums such as jelutong, lechi caspi, perillo, sorva, massaranduba balata, massaranduba chocolate, nispero, rosindinha, chicle, gutta hang kang, and combinations thereof. The preferred synthetic elastomer and natural elastomer concentrations vary depending on whether the chewing gum in which the base is used is adhesive or conventional, bubble gum or regular gum, as discussed below. Preferred natural elastomers include jelutong, chicle, sorva and massaranduba balata.
Elastomer plasticizers may include, but are not limited to, natural rosin esters such as glycerol esters or partially hydrogenated rosin, glycerol esters of polymerized rosin, glycerol esters of partially dimerized rosin, glycerol esters of rosin, pentaerythritol esters of partially hydrogenated rosin, methyl and partially hydrogenated methyl esters of rosin, pentaerythritol esters of rosin; synthetics such as terpene resins derived from alpha-pinene, beta-pinene, and/or d-limonene; and any suitable combinations of the foregoing. The preferred elastomer plasticizers will also vary depending on the specific application, and on the type of elastomer which is used.
Fillers/texturizers may include magnesium and calcium carbonate, ground limestone, silicate types such as magnesium and aluminum silicate, clay, alumina, talc, titanium oxide, mono-, di- and tri-calcium phosphate, cellulose polymers, such as wood, and combinations thereof.
Softeners/emulsifiers may include tallow, hydrogenated tallow, hydrogenated and partially hydrogenated vegetable oils, cocoa butter, glycerol monostearate, glycerol triacetate, lecithin, mono-, di- and triglycerides, acetylated monoglycerides, fatty acids (e.g. stearic, palmitic, oleic and linoleic acids), and combinations thereof.
Colorants and whiteners may include FDandC-type dyes and lakes, fruit and vegetable extracts, titanium dioxide, and combinations thereof.
The base may or may not include wax. An example of a wax-free gum base is disclosed in U.S. Pat. No. 5,286,500, the disclosure of which is incorporated herein by reference.
In addition to a water-insoluble gum base portion, a typical chewing gum composition includes a water-soluble bulk portion and one or more flavoring agents. The water-soluble portion can include bulk sweeteners, high-intensity sweeteners, flavoring agents, softeners, emulsifiers, colors, acidulants, fillers, antioxidants, and other components that provide desired attributes.
Softeners are added to the chewing gum in order to optimize the chewability and mouth feel of the gum. The softeners, which are also known as plasticizers and plasticizing agents, generally constitute between approximately 0.5% to about 15% by weight of the chewing gum. The softeners may include glycerin, lecithin, and combinations thereof. Aqueous sweetener solutions such as those containing sorbitol, hydrogenated starch hydrolysates, corn syrup and combinations thereof, may also be used as softeners and binding agents in chewing gum.
Bulk sweeteners include both sugar and sugarless components. Bulk sweeteners typically constitute about 5% to about 95% by weight of the chewing gum, more typically, about 20% to about 80% by weight, and more commonly, about 30% to about 60% by weight of the gum. Sugar sweeteners generally include saccharide-containing components commonly known in the chewing gum art, including but not limited to, sucrose, dextrose, maltose, dextrin, dried invert sugar, fructose, galactose, corn syrup solids, and the like, alone or in combination. Sugarless sweeteners include, but are not limited to, sugar alcohols such as sorbitol, mannitol, xylitol, hydrogenated starch hydrolysates, maltitol, and the like, alone or in combination.
High-intensity artificial sweeteners can also be used, alone or in combination, with the above. Preferred sweeteners include, but are not limited to, sucralose, aspartame, N-substituted APM derivatives such as neotame, salts of acesulfame, alitame, saccharin and its salts, cyclamic acid and its salts, glycyrrhizin, dihydrochalcones, thaumatin, monellin, and the like, alone or in combination. In order to provide longer lasting sweetness and flavor perception, it may be desirable to encapsulate or otherwise control the release of at least a portion of the artificial sweetener. Such techniques as wet granulation, wax granulation, spray drying, spray chilling, fluid bed coating, coacervation, and fiber extrusion may be used to achieve the desired release characteristics.
Combinations of sugar and/or sugarless sweeteners may be used in chewing gum. Additionally, the softener may also provide additional sweetness such as with aqueous sugar or alditol solutions.
If a low calorie gum is desired, a low caloric bulking agent can be used. Examples of low caloric bulking agents include: polydextrose; oligofructose (Raftilose); inulin (Raftilin); fructooligosaccharides (NutraFlora); palatinose oligosaccharide; guar gum hydrolysate (BeneFiber); or indigestible dextrin (Fibersol). However, other low calorie bulking agents can be used.
A variety of flavoring agents can also be used, if desired. The flavor can be used in amounts of about 0.1 to about 15 weight percent of the gum, and preferably, about 0.2% to about 5% by weight. Flavoring agents may include essential oils, synthetic flavors or mixtures thereof including, but not limited to, oils derived from plants and fruits such as citrus oils, fruit essences, peppermint oil, spearmint oil, other mint oils, clove oil, oil of wintergreen, anise and the like. Artificial flavoring agents and components may also be used. Natural and artificial flavoring agents may be combined in any sensorially acceptable fashion.
In general, chewing gum is manufactured by sequentially adding the various chewing gum ingredients to a commercially available mixer known in the art. After the ingredients have been thoroughly mixed, the gum mass is discharged from the mixer and shaped into the desired form such as rolling sheets and cutting into sticks, extruding into chunks or casting into pellets, which are then coated or panned.
Generally, the ingredients are mixed by first melting the gum base and adding it to the running mixer. The base may also be melted in the mixer itself Color or emulsifiers may also be added at this time. A softener such as glycerin may also be added at this time, along with syrup and a portion of the bulking agent. Further parts of the bulking agent are added to the mixer. Flavoring agents are typically added with the final portion of the bulking agent. Other optional ingredients are added to the batch in a typical fashion, well known to those of ordinary skill in the art.
The entire mixing procedure typically takes from five to fifteen minutes, but longer mixing times may sometimes be required. Those skilled in the art will recognize that many variations of the above described procedure may be followed.
After the ingredients are mixed, the gum mass is formed into pellets or balls. Pellet or ball gum is prepared as conventional chewing gum but formed into pellets that are pillow shaped, or into balls. The pellets/balls are used as cores for the coated product. The cores can be sugar or polyol coated or panned by conventional panning techniques to make a unique coated pellet gum. The weight of the coating may be about 20% to about 50% of the weight of the finished product, but may be as much as 75% of the total gum product.
Conventional panning procedures generally coat with sucrose, but recent advances in panning have allowed use of other carbohydrate materials to be used in place of sucrose. Some of these materials include, but are not limited to, sugars such as dextrose, maltose, isomaltulose, and tagatose or sugarless bulk sweeteners such as xylitol, sorbitol, lactitol, hydrogenated isomaltulose, erythritol, maltitol, and other new polyols (also referred to as alditols) or combinations thereof. The coating is preferably sugarless. These materials may be blended with panning modifiers including, but not limited to, gum arabic, gum talha, maltodextrins, corn syrup, gelatin, cellulose type materials like carboxymethyl cellulose or hydroxymethyl cellulose, starch and modified starches, vegetables gums like alginates, locust bean gum, guar gum, and gum tragacanth. Antitack agents may also be added as panning modifiers, which allow the use of a variety of carbohydrates and sugar alcohols. Flavors may also be added with the sugar or sugarless coating to yield unique product characteristics.
As noted above, the coating may contain ingredients such as flavoring agents, as well as dispersing agents, coloring agents, film formers and binding agents. Flavoring agents contemplated by the present invention include those commonly known in the art such as essential oils, synthetic flavors or mixtures thereof, including but not limited to oils derived from plants and fruits such as citrus oils, fruit essences, peppermint oil, spearmint oil, other mint oils, clove oil, oil of wintergreen, anise and the like. The flavoring agents may be used in an amount such that the coating will contain from about 0.2% to about 3% flavoring agent, and preferably from about 0.7% to about 2.0% flavoring agent.
High-intensity sweeteners contemplated for use in the coating include but are not limited to synthetic substances, saccharin, thaumatin, alitame, saccharin salts, aspartame, N-substituted APM derivatives such as neotame, sucralose and acesulfame-K. The high-intensity sweetener may be added to the coating syrup in an amount such that the coating will contain from about 0.01% to about 2.0%, and preferably from about 0.1% to about 1.0% high-intensity sweetener. Preferably the high-intensity sweetener is not encapsulated.
Dispersing agents are often added to syrup coatings for the purpose of whitening and tack reduction. Dispersing agents contemplated by the present invention to be employed in the coating syrup include titanium dioxide, talc, or any other antistick compound. Titanium dioxide is a presently preferred dispersing agent of the present invention. The dispersing agent may be added to the coating syrup in amounts such that the coating will contain from about 0.1% to about 1.0%, and preferably from about 0.3% to about 0.6% of the agent.
When high amounts of calcium carbonate or other antacid is used, the calcium carbonate is dispersed or suspended in the coating syrup that contains the sugar or polyol, thus making a syrup suspension. Generally, as the level of calcium carbonate is increased, the level of sugar or polyol is decreased. Levels of calcium carbonate used may be as low as 25% of the total solids or as high as 60% of the total solids in the syrup, and more preferably will comprise about 30% to about 40% of the total solids. In preferred embodiments, the calcium carbonate will comprise about 25% to about 60% of the gum coating, and more preferably about 30% to about 40% of the gum coating. The coating will preferably contain about 30% to about 75% maltitol.
Coloring agents are preferably added directly to the syrup suspension in the dye or lake form. Coloring agents contemplated by the present invention include food quality dyes. Film formers preferably added to the syrup include methyl cellulose, gelatins, hydroxypropyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose and the like and combinations thereof. Binding agents may be added either as an initial coating on the chewing gum center or may be added directly into the syrup. Binding agents contemplated by the present invention include gum arabic, gum talha, guar gum, karaya gum, locust bean gum, alginate gums, xanthan gum, arabinogalactan, various cellulose derivatives, vegetable gums, gelatin and mixtures thereof, with gum arabic being preferred. The binding agent is preferably used at a level of at least about 2% of the coating syrup.
The coating is initially present as a liquid syrup which contains from about 30% to about 80% of the coating ingredients previously described herein, and from about 20% to about 70% of a solvent such as water. In general, the coating process is carried out in a rotating pan. Sugar or sugarless gum center tablets to be coated are placed into the rotating pan to form a moving mass. The material or syrup suspension which will eventually form the coating is applied or distributed over the gum center tablets. Flavoring agents may be added before, during and after applying the syrup suspension to the gum centers. Once the coating has dried to form a hard surface, additional syrup additions can be made to produce a plurality of coatings or multiple layers of hard coating.
In a hard coating panning procedure, syrup is added to the gum center tablets at a temperature range of from about 100xc2x0 F. (38xc2x0 C.) to about 240xc2x0 F. (116xc2x0 C.). Preferably, the syrup temperature is from about 130xc2x0 F. (54xc2x0 C.) to about 200xc2x0 F. (94xc2x0 C.) throughout the process in order to prevent the polyol or sugar in the syrup suspension from crystallizing. The syrup suspension may be mixed with, sprayed upon, poured over, or added to the gum center tablets in any way known to those skilled in the art.
In general, a plurality of layers is obtained by applying single coats, allowing the layers to dry, and then repeating the process. The amount of solids added by each coating step depends chiefly on the concentration of the coating syrup suspension. Any number of coats may be applied to the gum center tablet. Preferably, no more than about 75-100 coats are applied to the gum center tablets. The present invention contemplates applying an amount of syrup sufficient to yield a coated comestible containing about 20% to about 75% coating.
Those skilled in the art will recognize that in order to obtain a plurality of coated layers, a plurality of premeasured aliquots of coating syrup suspension may be applied to the gum center tablets. It is contemplated, however, that the volume of aliquots of syrup suspension applied to the gum center tablets may vary throughout the coating procedure.
Once a coating is applied to the gum center tablets, the present invention contemplates drying the wet syrup suspension in an inert medium. A preferred drying medium comprises air. Preferably, forced drying air contacts the wet syrup coating in a temperature range of from about 70xc2x0 F. (21 xc2x0 C.) to about 115xc2x0 F. (46xc2x0 C.). More preferably, the drying air is in the temperature range of from about 80xc2x0 F. (27xc2x0 C.) to about 100xc2x0 F. (38xc2x0 C.). The invention also contemplates that the drying air possess a relative humidity of less than about 15 percent. Preferably, the relative humidity of the drying air is less than about 8 percent.
The drying air may be passed over and admixed with the syrup coated gum centers in any way commonly known in the art. Preferably, the drying air is blown over and around or through the bed of the syrup coated gum centers at a flow rate, for large scale operations, of about 2800 cubic feet per minute. If lower quantities of material are being processed, or if smaller equipment is used, lower flow rates would be used.
The present invention also contemplates the application of powder material after applying an aliquot of coating syrup to help build up the coating.
For many years, flavors have been added to a sugar coating of pellet gum to enhance the overall flavor of gum. These flavors include spearmint flavor, peppermint flavor, wintergreen flavor, and fruit flavors. These flavors are generally preblended with the coating syrup just prior to applying it to the core or added together to the core in one or more coating applications in a revolving pan containing the cores. Generally, the coating syrup is very hot, about 130xc2x0 F. (54xc2x0 C.) to 200xc2x0 F. (93xc2x0 C.), and the flavor may volatilize if preblended with the coating syrup too early.
The coating syrup is preferably applied to the gum cores as a hot liquid, the sugar or polyol allowed to crystallize, and the coating then dried with warm, dry air. Aliquots of syrups are preferably applied in about 30 to 80 applications to obtain a hard shell coated product having an increased weight gain of about 20% to 75%. A flavor is applied with one, two, three or even four or more of these coating applications. Each time flavor is added, several non-flavored coatings are applied to cover the flavor before the next flavor coat is applied. This reduces volatilization of the flavor during the coating process.
For mint flavors such spearmint, peppermint and wintergreen, some of the flavor components are volatilized, but sufficient flavor remains to give a product having a strong, high impact flavor. Fruit flavors, that may contain esters, are more easily volatilized and may be flammable and/or explosive and therefore, generally these type of fruit flavors are not used in coatings.

Coated chewing gum products containing antacid and method of making